Chuck for crown closure lining apparatus

ABSTRACT

A chuck to be fitted on the rotatable spindles of crown closure lining machines is adapted to center and hold both normal crowns and crowns having protruding tabs, and hold them in centered position despite the off-centering effect of the tab. The chuck has a shallow rim which surrounds the seated crown, a narrow shoulder on which the crown seats, and an inwardly directed conical bore leading to a vacuum passage through the spindle.

United States Patent [191 Boulton A r. 2 1974 [54] CHUCK FOR CROWN CLOSURE LlNlNG 3,220,381 ll/l965 Alholm .4 279/3 X APPARATUS 3,454,282 7/1969 Harrison et al. 279/3 98,820 [/1870 Warner 279/3 [75} Inventor: Richard C. Bnulton, Wilmington, 83 220 9 1954 n0u1 5l/235 M355. 3,437,343 4/l969 (ircck t .t 279/3 6 i. 3 [73] Assignec: W. R. Grace & C0., Cambridge, 3/197] Harmon ct 279/ Mass.

Primary Examiner-Andrew R. Juhasz [22] Ffled' 1973 Assistant Examiner-Z. R. Bilinsky [2]] Appl. No.: 331,418 Attorney, Agent, or FirmArmand McMillan; C. E.

Related us. Application Data Parke? Bake [60] Continuation of Ser. No. 92,942, Nov. 25, l970, abandoned, Division of Ser. No. 809,505, March 24, 1969, abandoned. [57] ABSTRACT A chuck to be fitted on the rotatable spindles of [52] Cl crown closure lining machines is adapted to center [5 1 Int Cl 13/02 and hold both normal crowns and crowns having pro- [58] Field o'f'e'e'e'i; 355/5-389/21- 31/235- thin q-enwegwpogitm 425/809 'i6f' f 18/318 50 spite the off-centering effect of the tab. The chuck has a shallow rim which surrounds the seated crown, a

narrow shoulder on which the crown seats, and an in- 5 References Cited wardly directed conical bore leading to a vacuum passage through the spindle.

1 Claim, 4 Drawing Figures EATENTEB 2 1974 FIG.

FIG. 4

CHUCK FOR CROWN CLOSURE LINING APPARATUS This application is a continuation of U.S. Pat. application Ser. No.' 92,942 filed Nov. 25, 1970, and now abandoned, which is a divisional of U.S. Pat. application Ser. No. 809,505 filed Mar. 24, 1969 and now abandoned.

This application is a division of U.S. Pat. application, Ser. No. 809,505 filed Mar. 24, I969.

This invention relates to chucks used with crown closure lining machines. Its important attribute is that, besides accepting normal crowns, it successfully centers tab-type crowns on the rotating chuck and holds them in proper position during the lining operation, despite the offcentering effect of the protruding tab.

Crown closures are made by feeding the crown shells from an unscrambling device to a rotating chuck on which the crown shells ride in an upside-down position. As soon as the crowns are seated on the chuck, a charge of sealing compound is ejected into the shell, usually through a pneumatic nozzle which is positioned just above the spinning crown. The rotation is very rapid to provide the centrifugal force necessary to uniformly distribute the sealing composition across the panel portion of the crown and bank a major amount against the interior walls of the skirt to form the sealing gasket.

For crowns with the normal configuration, previously designed chucks have worked very well, but recently there has been a popular demand for a crown which can be lifted off of the bottle by pulling a tab which protrudes outwardly from the margin of the skirt. This tab, producing as it does a dynamically unstable system when it is rotated at high speed, has, when it was attempted to line tab-crown shells on conventionally equipped lining machines, caused all sorts of troubles in the way of off-centering, lost crowns, and jamming. The design of the present chuck overcomes these difficulties, and tab crowns can be lined on conventional lining machinery merely be substituting my improved chuck for chucks previously found satisfactory for normal crowns.

In the accompanying drawings,

FIG. 1 is a vertical elevation, partially sectionalized, of the chuck.

FIG. 2 is a partial cross-section of the lip and floor of the chuck.

FIG. 3 is a plan view looking down on the chuck from above.

FIG. 4 is a side vertical elevation, partly in section showing the chuck in position within a spindle of a conventional lining machine.

The chuck, 10, comprises a crown-receiving head, 11, having, preferably, as shown, an exterior conical configuration, surmounting a shaft portion, 12. The head, 11, has a concentric conical bore 13, which communicates with axial bore, 14, within shaft portion 12. A pilot surface, 15, is formed on the lower face of a collat-like extension, 16, on the shaft, 12. Another pilot surface, 17 is cylindrical and is formed on the exterior of shaft portion 12. The lower portion of shaft 12 carries an external left-handed thread, 18, to attach the chuck to the spindle support bearing shown in FIG. 4 of the lining machine. Cylindrical pilot surface 14, sets the height of the chuck in the spindle accurately. The hexagonally broached portion, 19, of the bore, 14, permits a hexagonal wrench to be inserted to screw the chuck on and off the machine spindle.

An upstanding peripheral rim, 20, approximately 0.036 of an inch high is formed at the chuck periphery. The internal wall, 21, of rim, 20, merges into the floor. 22, of a narrow shoulder, 23. Floor, 22, slopes d0wnwardly at an angle of about 4.

In FIG. 4, the chuck of the invention is shown in position in the spindle of a conventional lining machine. Chuck shaft, 24, is suitably mounted on the end of a lifting beam (not shown) raised and lowered by suitable cam means (also not shown). Chuck shaft 24 has a concentric bore, 25, which communicates with bore 14 of the chuck. Air exhaust means (not shown) are connected to the lower end of shaft 24 to draw air through conical bore 13, and concentric bores 14 and 25.

Chuck shaft 24, which is quill mounted, both rotates and reciprocates axially in bearing 26 and is keyed to the bearing at 27. Rotative movement is provided by gear 28 which is threaded and keyed to the lower end of bearing 26. A threaded nut 29 locks the gear 28 on the hearing.

A collar, 30, is shown positioned between the chuck 10 and chuck shaft 24 into which the chuck is inserted. While the use of collar 30 is optional, such is highly desirable in order to prevent spattered lining compound dispensed from nozzle 31 from entering the spindle bearing.

Although magnets may be used to attract and hold the crown in proper position, it is a general practice today, because non-magnetic metals are commonly used, that crowns be held on the chuck by differential air pressure. In the chuck described above crown 32 is held onto the chuck by differential pressure brought about by pulling a vacuum through communicating bore l3, l4 and 25.

The operation of the device is as follows: tab-type crown 32 is delivered to the chuck by suitable means (not shown); when the closure approaches the zone of inward air flow, i.e., air passing from the atmosphere of the room into the bore of the chuck, it is drawn over the spinning rim, 20, and pulled toward the center of rotation and so becomes centered within the confines of the pocket formed between the rim, 20, and the shoulder, 23. As soon as this happens, air flow through the bores 13 and 14 is cut off by the closure itself, and this differential pressure, plus the effect of the rim, prevents the crown from spinning off. The seating and centering is so secure that even the centrifugal force devel oped by the offcentered pull tab will not dislodge a tab-type crown. Removal of the crown is effected by reciprocating fingers 33.

The depth of conical bore 13 is preferably at least one-half of the base diameter of the conical bore.

For crowns of approximately 26 mm across the top panel, the height of the cone portion, 11, is about onehalf an'inch. The inside diameter of the rim, 20, forming the crown pocket, is then nominally 1.054 inches. A considerable portion of the air rushing into the bore, 13, from the surrounding atmosphere flows at an angle which can be no less than that of the conical wall This angular air flow pattern adds materially in the rapid centering of the crown, and the fact that the crown can seat only on a relatively narrow rim produces a good seal-off which securely holds the crown by the differential air pressure which develops the in stant the crown becomes seated.

In consequence, machines can be equipped with chucks of this type and thereafter will operate interchangeably on normal or tab-type crowns without further adjustment.

I claim:

1. An apparatus for lining crown closures with sealing composition including a. A chuck shaft having a hollow bore, said shaft being axially rotatable and reciprocatable in bearing means supported by a frame;

b. a chuck for receiving unlined crown closures, the chuck comprising an upper crown-receiving head portion and a lower shaft portion, the uppermost end of said head portion having a crown pocket formed by an upstanding peripheral rim and a conical bore concentric with said rim having a base area which includes a major portion of the area of said pocket, said conical bore having a depth of at the hollow bore of said chuck shaft; 0. means positioned above said chuck for dispensing sealing composition into a closure crown carried by said chuck; and

d. reciprocating means carried by said frame for removing closures from said chuck after dispensing of the sealing composition in the closure. 

1. An apparatus for lining crown closures with sealing composition including a. A chuck shaft having a hollow bore, said shaft being axially rotatable and reciprocatable in bearing means supported by a frame; b. a chuck for receiving unlined crown closures, the chuck comprising an upper crown-receiving head portion and a lower shaft portion, the uppermost end of said head portion having a crown pocket formed by an upstanding peripheral rim and a conical bore concentric with said rim having a base area which includes a major portion of the area of said pocket, said conical bore having a depth of at least one half of the base diameter of said bore, the walls of which bore converge at acute angles whereby an angular air flow pattern converging into said bore is established and becomes effective to center the crown on said chuck, said lower shaft portion having an axial bore communicating with said conical bore, said chuck being mounted upon said chuck shaft in a manner such that said axial bore of said lower shaft portion communicates with the hollow bore of said chuck shaft; c. means positioned above said chuck for dispensing sealing composition into a closure crown carried by said chuck; and d. reciprocating means carried by said frame for removing closures from said chuck after dispensing of the sealing composition in the closure. 